Empirical Channel Modeling for Multi-Molecule Molecular Communication: An Experimental Fluorescence-Based Approach

Abstract

Molecular communication (MC) is a new communication paradigm in which molecules are employed as information carriers. An essential requirement for the design of reliable MC systems is the characterization of the communication channel. Despite significant advances in conceptual modeling, there is an extensive gap between theoretical models and the physical behavior observed in real-world environments. An often more effective approach relies on the adoption of empirical channel models, which can more accurately capture the behavior of the channel under a specific scenario. Along this line, we present a methodology to derive an empirical channel model for a multi-molecule MC (MM-MC) system based on fluorescence in advection–diffusion channels. In this framework, two distinct types of fluorescent molecules are employed to transmit information, enabling the implementation of Molecular Shift Keying (MoSK) and molecule type Multiple-Input Multiple-Output (mtMIMO) schemes. The proposed approach analyzes the channel response in both spatial and temporal domains, with particular attention to the inter-symbol interference (ISI) resulting from molecular interactions within the channel. Furthermore, the interference caused by the simultaneous use of different molecular types is modeled and integrated into the channel characterization. In addition, we propose a novel low complexity non-coherent detection scheme for both MoSK and mtMIMO configurations, which includes a simple interference mitigation. To develop and validate the proposed model and detection scheme, an experimental testbed was implemented and used to emulate realistic MC scenarios. The obtained results demonstrate the feasibility of fluorescence-based MM-MC systems employing mtMIMO and MoSK techniques.